The present invention relates to a sanitary coupling which connects an inflow-side and an outflow-side line section to each other, with a sanitary insert element which has an insert housing designed as an insert cartridge, which insert housing is inserted via an end-side insert opening into a housing receptacle in a first line section until an annular flange, which serves as an insert stop, on the insert housing acts upon an end circumferential edge of the first line section, said end circumferential edge bounding the insert opening, wherein the insert housing has a housing interior which communicates with the ambient air, wherein an annular zone is provided between the housing outer circumference of the insert housing and the inner circumference of the housing receptacle, said annular zone, in a partial region, having at least one air duct which is effective between the housing interior and the housing outer circumference, and wherein an air gap between the housing outer circumference and the inner circumference of the housing receptacle is arranged in the partial region of the annular zone, which partial region is arranged between the annular flange and the at least one annular seal.
Such sanitary couplings which connect two line sections to each other are already known in various embodiments. Such sanitary couplings are used, for example, in order to connect a hand-held shower or similar point of water consumption, on the one hand, to a water connection, on the other hand. In this case, one line section, and in particular the outflow-side line section, can have a housing receptacle which is generally designed as a cross-sectional extension of the clear through flow cross section and into which an insert housing designated as an insert cartridge is insertable until an annular flange, which serves as an insert stop, on the insert housing acts upon an end circumferential edge of the first line section, said end circumferential edge bounding the insert opening. If pressure is intended to be equalized in the housing interior of the insert housing or if ambient air is intended to be sucked into the housing interior and mixed there, for example, with the water flowing therethrough, the housing interior should be connected to the ambient air and at the same time care should also be taken to ensure a liquid-tight connection of the two line sections.
EP 2 756 878 A1 discloses a sanitary coupling which connects a hand-held shower to an inflow-side flexible shower hose. At its end facing the shower hose, the hand-held shower has a housing receptacle into which an inert element which serves as a jet aerator is insertable. Ventilation openings are provided in the insert housing of the previously known insert element, via which ventilation openings ambient air can be sucked into the housing interior and is supplied via the screw connection between the hand-held shower and the adjacent shower hose. However, the air conduction in the previously known sanitary coupling is guided via narrow gaps, which can have a limiting effect on the supply of air.
US 2012/248221 A1 already discloses a sanitary coupling of the type mentioned at the beginning which connects an inflow-side first line section and an outflow-side second line section to each other. The sanitary coupling which is designed as a water-saving unit and, to this end, is intended to enrich the water flowing therethrough with ambient air has an inflow-side first coupling part and an outflow-side second coupling part which are connected releasably to each other. The inflow-side first coupling part, which serves at the same time as an insert housing for a filter sieve, is inserted with an inflow-side coupling-part section via an end-side insert opening into a housing receptacle in the inflow-side first line section and is secured therein via a screw connection provided between the coupling part and the line section. In this case, an annular flange, which serves as an insert stop, on the insert housing acts upon the end circumferential edge bounding the insert opening of the first line section. The inflow-side coupling part has an outflow-side coupling-part section which protrudes in the manner of a pin over the first coupling-part section and opens in the outflow-side line section. In the partial region arranged between its coupling-part sections, the inflow-side first coupling part has radially oriented ventilation ducts, in each of which a non-return valve is provided. These ventilation ducts connect an annular zone, which remains between the coupling parts, to the liquid-conducting housing interior of the inflow-side first coupling part, wherein an outflow of the water flowing through the coupling part is prevented by the non-return valves. By the water flowing through the previously known coupling, ambient air is sucked in the manner of a water jet pump via the ventilation ducts into the liquid-conducting housing interior of the sanitary coupling and mixed there with the water flowing therethrough.